Hi! For A Couple Of Months Now I Have Been

Hi! For a couple of months now I have been scratching a certain spot on my left lower leg. It's itching like crazy sometimes, specifically after noon every now and then. Now, after that spot has been practically skinned and looks a bit like a bruising surrounding it, the itch have ''transferred'' onto my right leg. What I find weird and a tad scary is that the itching looks like it is mirroring my left leg by the placement of the new bruise. They are not larger than around 1cm. But I scratch until I draw blood. It still won't go away.